Generally, the space where Koyo bearings can be installed is limited. In most cases, the shaft diameter (or Koyo bearing inner diameter) is limited by mechanical design or other design. Therefore, the selection of bearing type and size is determined according to the inner diameter of the bearing. Therefore, the main dimension tables of standard Koyo bearings are prepared according to the international standard inner diameter dimensions. Standard Koyo bearings have various sizes and forms. Standard Koyo bearings are used in mechanical device design (this is designed to make KOYO bearings easy to purchase.
Here’s a digression. Some of the bearings catalog models do have some, but some non-standard KOYO bearings are not available in Chinese mainland, and sometimes futures will be very long time, so when bearing selection, we should consider the cost of time and the cost of later replacement). The nature, size and direction of the load of the bearing and the load applied on the Koyo bearing are variable. Generally, the rated basic load is shown in the size table. However, axial load and radial load are also important factors for selecting suitable Koyo bearings. When the sizes of ball and needle roller bearings are the same, needle roller Koyo bearings usually have high load capacity and bear large vibration And impact load.
The allowable speed is determined according to Koyo bearing type, size, accuracy, cage type, load, lubrication mode, cooling mode and other factors. The Koyo bearing table lists the allowable speed of standard precision bearings under oil lubrication and grease lubrication. Generally, deep groove ball bearings, self-aligning ball bearings and cylindrical roller bearings are suitable for high-speed operation. Thirdly, Koyo bearing tolerance. The dimensional accuracy and rotation accuracy of Koyo bearings are based on ISO and JIS standards.
For machines requiring high accuracy and high-speed operation, it is recommended to use bearings with accuracy of grade 5 or above. Deep groove ball bearings, centripetal thrust ball bearings or cylindrical roller bearings are suitable for machines with high operation accuracy. Rigidity. Elastic deformation will occur when the contact surface of rolling elements and raceways of bearings is pressed. Some machines It is necessary to minimize the elastic deformation. Roller bearings produce less elastic deformation than ball bearings.
In addition, in some cases, Koyo bearings need to be preloaded to increase rigidity. This procedure is usually used for deep groove ball bearings, centripetal thrust ball bearings and tapered roller bearings. Inner and outer ring offset, shaft bending, tolerance change of shaft or Koyo bearing housing and matching error will lead to inner and outer ring eccentricity. In order to prevent excessive eccentric angle, self-aligning ball bearing, self-aligning roller bearing, or self-aligning bearing seat are better choices. Voice frequency and torque, rolling bearings are manufactured according to high-precision standards, so voice and torque are small.
Deep groove ball bearings and cylindrical roller bearings are suitable for occasions with special requirements for low noise and low torque. Installation and disassembly. Some applications require frequent disassembly and installation to ensure regular inspection and maintenance. Koyo bearings with separate inner and outer rings, such as cylindrical bearings, needle roller bearings and conical bearings, are very suitable for this occasion. With the help of the shaft sleeve, the installation procedure of the taper hole self-aligning ball bearing and self-aligning roller bearing is also simplified.
(1) Before the installation of Koyo bearing, the processing quality of shaft, seat hole and relevant parts (such as dimensional accuracy, shape accuracy and surface roughness) shall be checked with appropriate measuring tools according to the technical requirements on the design drawing.
(2) If there are bumps, burrs, rust spots or solid particles (such as wear debris, sand and soil) on the assembly surface of the shaft and bearing seat hole, it will not only make the installation of Koyo bearing difficult and the installation position incorrect, but also the solid particles will play a grinding role if they fall into the Koyo bearing, and the working surface of Koyo bearing will be abraded or scratched when the Koyo bearing rotates, Therefore, it must be carefully checked before installation. If the above defects are found, they should be corrected. For example, use an oil file to remove burrs, raised bumps and rust spots, and polish them with fine abrasive cloth, such as cleaning solid particles, dirt, etc.
(3) The assembly surface shall be cleaned with clean gasoline, kerosene, toluene or xylene solution, wiped dry with clean cloth, and then coated with a thin layer of lubricating oil, which can make the installation and operation more convenient.
(4) Before installation, open the Koyo bearing package, immerse it in the above gasoline and other liquids and rotate it gently by hand. Ensure that the sealing oil on the cage, rolling element and raceway surface is completely cleaned.
(5) When cleaning a large number of Koyo bearings, first scald them with hot engine oil with a temperature of 90 ~ 100 ℃ to melt the sealing oil. At the same time, dig out all the old oil with a seamless tool without falling debris, then scald them for a few minutes, then rinse off the engine oil with kerosene, and then clean them with gasoline. After cleaning, wear film gloves and put the bearing on a clean cloth or paper on the workbench to dry.
(6) Note that the bearing with seal can not be cleaned by this method, and the inside of the seal should be kept as it is and can not be cleaned.